Analgesia following intraventricular administration of 2-deoxy-D-glucose

The glucose analogue, 2-deoxy-D-glucose (2-DG) elicits hyperphagic and analgesic responses in rats. The former response appears to be mediated by central processes since overeating is elicited following intraventricular administration of 2-DG at low (3.5 and 5.0 mg/kg) doses. The present study examined whether flinch-jump threshold would increase 30, 90 and 180 min following intraventricular injections of 2-DG at low (3.5, 5.0 and 10.0 mg/kg) doses and compared these effects with systemically-applied 2-DG doses of 350 and 500 mg/kg. Intraventricular 2-DG administration increased jump thresholds for up to 180 min across all test doses. Flinch thresholds were also increased, but in a manner dissociated from jump thresholds. Animals with cannulae located near, but not in the lateral ventricle, displayed delayed analgesic effects. The magnitude of intraventricular 2-DG analgesia was not at potent as the 100-fold higher systemic injections. It appears that central mechanisms mediated intraventricular 2-DG analgesia at the low dose range since higher, systemic 2-DG doses have previously failed to increase flinch-jump thresholds.